Question Allow docker services to access host services

[Stefan S.]

Hi,

today I noticed, that my firewall allowed all incoming ports. So I went to the firewall and changed the option "System policy for incoming traffic" to "Deny".
Now all ports are blocked which have not been whitelisted.

My problem is now, that my docker services (like Gitlab) can't connect to my host anymore.
My docker0 interface has the IP 172.17.0.1.
I went to the MySQL service and switched to "Allow from selected sources, deny from others" and added following IPs:

* 127.0.0.1
* 172.17.0.0/24

Unfortunately my apps get a timeout when trying to connect to MySQL.

My docker images use following settings:

* DB_HOST => 172.17.0.1
* DB_PORT => 3306

I tried rebooting my server and also restarting the docker service after changing the firewall settings.

How can I fix this problem? :-/

Best Regards,
Stefan

 

[Stefan S.]

Do I maybe need to forward the traffic?
Or is a rule for incomming traffic enough?